[ire]

I built up my new cross bike and I've been having issues with the rear shifting and I was wondering if anyone else has had a similar experience; I have a SRAM PC1030 chain with an Ultegra der. and a 105, 12-25t cassette. I've tried changing the der, and the cassette and I'm still having problems. It shifts great until about midway down and then down shifting starts to suck, upshifts great through all gears. It seems like the cassette cogs are too close in size and the der. has trouble pulling the chain down. Both of the cassettes I've tried are 12-25....would an 11-25 shift better? I'm a bit mystified

<edit> I think it may be the chain, I was looking on another bike and I have the same setup w/shimano chain instead and it shifts fine

 

[MtnbikeMike]

Check the derailleur hanger alignment. Could be the culprit by the way you describe it.

Edit: Buy SRAM

 

[loco-gringo]

It sounds like the hanger. Even though things were packed up well, it could still be a bit off. I had that on a bike last week. If you have someone with an alignment guage it will be squared away in no time. I run sram chains on shimano and campy and don 't have any issues. If you need a hanger, let me know.

 

[-dustin]

why did you choose a SRAM chain?

what kind of shifters?

what kind of cables and housing?

i'm going the other way and will say that it sounds like a cable/ housing/ cable guide friction issue.

 

[nmr8]

<edit> I think it may be the chain, I was looking on another bike and I have the same setup w/shimano chain instead and it shifts fine

i believe the chain is absolutely compatible. as other people have said you probably have a tweaked hanger, or bad cable/housing, or a nine-speed/ten-speed mismatch between your cassette and shifter. (or a SRAM/Shimano mismatch between your derailleur and shifter.) Shimano and SRAM ten-speed chains and cassettes are interchangeable, while the shifters/derailleurs are not.